/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/db/pipeline/granularity_rounder.h"

#include "mongo/util/assert_util.h"
#include "mongo/util/str.h"
#include "mongo/util/string_map.h"

#include <boost/smart_ptr/intrusive_ptr.hpp>

namespace mongo {

using Rounder = GranularityRounder::Rounder;

namespace {
// Used to keep track of which GranularityRounders are registered under which name.
StringMap<Rounder> rounderMap;
}  // namespace

void GranularityRounder::registerGranularityRounder(StringData name, Rounder rounder) {
    auto it = rounderMap.find(name);
    massert(40256,
            str::stream() << "Duplicate granularity rounder (" << name << ") registered.",
            it == rounderMap.end());
    rounderMap[name] = rounder;
}

boost::intrusive_ptr<GranularityRounder> GranularityRounder::getGranularityRounder(
    const boost::intrusive_ptr<ExpressionContext>& expCtx, StringData granularity) {
    auto it = rounderMap.find(granularity);
    uassert(40257,
            str::stream() << "Unknown rounding granularity '" << granularity << "'",
            it != rounderMap.end());
    return it->second(expCtx);
}
}  // namespace mongo
